Field of the Invention
The present invention relates to a thermoelectric converter which could be compact and has high nonconductivity.
A conventional thermoelectric converter which is shown in Japanese unexamined Patent (Kokai) No. 53-99796, as shown in FIG. 27, has a thermoelectric converting portion 80, an endothermic heat exchanger 81 and a radiative heat exchanger 82 for radiating and absorbing heat by the Peltier effect. The thermoelectric converting portion 80 comprises a plurality of P-type thermoelectric elements (P-type semiconductor) 1p' and N-type thermoelectric elements (N-type semiconductor) 1n' which are disposed one after the other, a plurality of endothermic electrodes 83 which connect an end of the P-type thermoelectric element 1p' with an end of the N-type thermoelectric element 1n' and a plurality of radiative electrodes 84 which connect the other end of the P-type thermoelectric element 1p' with the other end of the N-type thermoelectric element 1n'.
The endothermic heat exchanger 81 includes a insulating plate 85 which is thermally connected to the endothermic electrodes 83, and an endothermic metal plate 86 which is thermally connected to the insulating plate 85.
The radiative heat exchanger 82 includes an insulating plate 87 which is thermally connected to the radiative electrode 84, and a radiative metal plate 88 which is thermally connected to the insulating plate 87.
The radiative electrode 84a is connected to a negative pole of an electric supply (not shown) and the radiative electrode 84b is connected to a positive pole. The endothermic electrodes 83 absorb heat, and then the endothermic metal plate 86 is cooled. The radiative electrodes 84 radiate heat, and then the radiative metal plate 88 is heated.
In the conventional device described above, the insulating plates 85 and 87 are disposed between the electrodes 83 and 84 and the metal plates 86 and 88 in order to prevent short-circuits between the adjacent endothermic electrodes 83 and the adjacent radiative electrodes 84. The insulating plates 85, 87 decrease the efficiency of radiating and absorbing heat due to the thermal resistance of the insulating plates 85, 87 and the contacting thermal resistance between the endothermic metal plate 86 and the insulating plate 85, the insulating plate 85 and the endothermic electrode 83, the radiative electrode 84 and the insulating plate 87, the insulating plate 87 and the radiative plate 88.
Since an electric current flows through each of electrodes 83, 84, Joule heat is generated due to the electric resistance of electrodes 83, 84 and the efficiency of cooling is decreased. The cross sectional area of the electrodes 83, 84 across the direction of the electric current is small and the length of the electrodes 83, 84 along the direction of the electric current is long, so the electric resistance becomes larger and the Joule heat increases.
If the length of the electrodes 83, 84 becomes shorter, a short circuit might be caused between adjacent electrodes 83 and/or between adjacent electrodes 84. For instance, when the length of the endothermic electrode 83 becomes shorter, two of the radiative electrodes 84 come closer. In other words, enough distance between adjacent electrodes is required to avoid a short circuit, so that it is hard to make the device compact.
If adjacent electrodes short circuit, the thermoelectric elements could not radiate or absorb heat.